Cohort initial characteristics
| Characteristics | Total (N=3447) | Not intubated (n=2733) | Intubated (n=714) | P value |
| Demographics | ||||
| Age | 49.4 | 47.0 | 58.4 | 0.01 |
| Percent female | 51.5 | 54.3 | 40.6 | <0.01 |
| Weight (kg) | 89.3 | 89.2 | 89.6 | 0.37 |
| Body mass index | 32.8 | 32.6 | 33.6 | <0.01 |
| Comorbidities (not used in modeling) | ||||
| Chronic Obstructive Pulmonary Disease (%) | 7.9 | 6.1 | 14.8 | <0.01 |
| Asthma (%) | 13.3 | 13.3 | 13.3 | <0.01 |
| Heart failure (%) | 11.3 | 7.2 | 26.9 | <0.01 |
| Diabetes (%) | 34.7 | 29.4 | 54.9 | <0.01 |
| Labs and vital signs | ||||
| Bilirubin (mg/dL) | 0.65 | 0.64 | 0.69 | <0.01 |
| BUN (mg/dL) | 24.33 | 23.60 | 27.14 | 0.40 |
| BUN:creatinine ratio | 23.85 | 23.55 | 25.01 | 0.02 |
| Calcium (mg/dL) | 8.68 | 8.73 | 8.49 | <0.01 |
| Chloride (mEq/L) | 101.38 | 101.42 | 101.25 | 0.01 |
| D-dimer (ng/mL) | 188.57 | 173.81 | 245.09 | <0.01 |
| Fraction of inspired oxygen (%) | 58.96 | 59.05 | 58.63 | <0.01 |
| Glasgow Coma Scale | 13.39 | 13.68 | 12.29 | <0.01 |
| Glomerular filtration rate (mL/min) | 82.09 | 83.27 | 77.59 | <0.01 |
| Glucose (mg/dL) | 146.36 | 143.33 | 157.98 | 0.35 |
| Hematocrit (%) | 35.86 | 35.67 | 36.61 | 0.01 |
| Hemoglobin (g/dL) | 11.83 | 11.77 | 12.06 | 0.03 |
| Lymphocyte count (109/L) | 1.29 | 1.32 | 1.17 | <0.01 |
| Lymphocytes (%) | 16.40 | 17.15 | 13.52 | <0.01 |
| Mean corpuscular hemoglobin (g/dL) | 29.26 | 29.26 | 29.24 | <0.01 |
| Mean corpuscular hemoglobin concentration (g/dL) | 32.53 | 32.55 | 32.46 | 0.46 |
| Mean corpuscular volume (fL) | 89.88 | 89.84 | 90.01 | <0.01 |
| Mean platelet volume (fL) | 10.52 | 10.51 | 10.58 | <0.02 |
| mSOFA score | 3.62 | 3.18 | 5.30 | 0.28 |
| Oxygen saturation (%) | 93.85 | 93.93 | 93.54 | 0.16 |
| Platelet count (109/L) | 257.96 | 257.30 | 260.48 | <0.01 |
| Red blood cell count (1012/L) | 4.07 | 4.06 | 4.09 | 0.35 |
| Red cell distribution width (%) | 14.76 | 14.80 | 14.62 | 0.02 |
| Red cell distribution width, SD (fL) | 47.86 | 47.95 | 47.50 | <0.01 |
| Temperature (°F) | 98.42 | 98.40 | 98.50 | <0.01 |
| White cell count (thousand/µL) | 89.24 | 89.15 | 89.57 | 0.37 |
The table shows the distribution of comorbidities and mean initial physiological metrics used in model training for the overall cohort, intubated patients and non-intubated patients.
BUN, blood urea nitrogen; mSOFA, modified Sequential Organ Failure Assessment.